Abstract: A microwave applicator for insertion into living body tissue for use in microwave coagulation and ablation treatments includes a microwave transmission line extending between an attachment end of the applicator and an antenna toward an insertion end of the applicator with an outer conductive sleeve forming an enclosed fluid space around the transmission line. A fluid circulation system circulates fluid in the fluid space. A portion of or all of the circulating fluid can be injected into tissue that surrounds the applicator body from approximately the proximal end of a desired heating zone produced by microwave energy radiated from the antenna along the applicator body toward the proximal end of the applicator to hydrate and wet the tissue outside the proximal end of the desired heating zone to reduce the drying of this tissue and limit extension of the heating and ablation zone proximally along the applicator body.

Abstract: An emitter assembly can include a proximal shaft, a distal shaft, a shunt that connects the proximal shaft to the distal shaft, and a tip that is connected to a distal end of the distal shaft. An inner conductor can extend through the proximal shaft, the shunt, and the distal shaft and into the tip to provide microwave energy to the tip. An outer conductor can extend into the shunt. The shunt can therefore form an electrical connection between the outer conductor and a proximal ring of electrically conductive material formed on an exterior surface of the distal shaft. Distal shaft can be made of a thermally conductive but electrically insulated material to facilitate transfer of heat from the distal shaft to the proximal shaft.

Abstract: A microwave applicator for insertion into living body tissue for use in microwave coagulation and ablation treatments includes a microwave transmission line extending between an attachment end of the applicator and an antenna toward an insertion end of the applicator with an outer conductive sleeve forming an enclosed cooling fluid space around the transmission line. Circulation of cooling fluid is guided in the cooling fluid space by a guide sleeve. A fluid circulation system provides a plurality of fluid supply connectors and fluid return connectors which can be connected and used with any number of applicators between one and the number of the fluid supply connectors provided by the system. A portion of the applicator inserted into the tissue can stick to the tissue to stabilize the applicator during treatment. A warning marking on the applicator can be used during track ablation to prevent ablation of the patient skin tissue.